Acyldesilylation of 5-Trimethylsilyl-2-furancarboxaldehyde

5－Acyl－2－furancarboxaldehydes2arelmpol－tantIntermedlateslforsynthesizingnaturallyoccuTTingfuranoldfattyacidswhichhaveantloxldanteffectsandantlneoplastlcactlvltlesInbiologicalsystems－．Nakayamaela尸reportedsuccessfulhalodesllylatlonofethyls－trlm...     

A CASCI-MRMP method based on Kohn—Sham orbitals

Kohn-Sham orbitals are used in the previously proposed CASCI-MRMP scheme (a multi-reference M?ller-Plesset (MRMP) method with a complete active space configuration interaction (CASCI) reference function). That is, the CASCI wave function was constructed using the Kohn-Sham orbitals and used as a reference function of the MRMP to incorporate the remaining dynamical correlation. The scheme was applied to the potential curves of the ground and low-lying excited states of N₂, the potential curve of the ground state of CO, the barrier height of the H₂CO → H₂ + CO reaction, the valence π-π? and Rydberg excited states of benzene, and the low-lying excited states of ozone. Good agreement between the theory, experiment, and some benchmark calculations was obtained. The various orbitals which are investigated here do not give very different results. Rather, the choice of active space makes a considerable difference, and in particular the perturbation calculation is proved to be very important.     

AN EULERIAN FINITE ELEMENT METHOD FOR TIME-DEPENDENT FREE SURFACE PROBLEMS IN HYDRODYNAMICS

A numerical method based on the finite element method is presented for simulating the two-dimensional transient motion of a viscous liquid with free surfaces. For ease of numerical treatment of the free surface expressed by a multiple-valued function, the marker particle method is employed. Numerous virtual particles are spread over all regions occupied by liquid. They move about on a fixed finite element mesh with the liquid velocity at their positions. These particles contribute nothing to the dynamics of the liquid and only serve as markers of liquid regions. The velocity field within liquid regions is calculated by solving the Navier– Stokes equations and the equation of continuity by the finite element method based on quadrilateral elements. A detailed discussion is given of the methodological problems arising in the implementation of the marker particle method on an unstructured finite element mesh and of the solutions to these problems. The proposed method is demonstrated on three sample problems: the broken dam problem, the impact of a falling liquid drop on a still liquid and the entry of a rigid block into water. Good agreement has been obtained in the comparison of the present numerical results with available experimental data.     

具有3个次级晶格结构的钛酸盐晶体[Ni(OH)1.115(H2O)0.885]1.22(Ti1.73O4)·1.65H2O的合成

以K0.81Li0.27Ti1.73O4为前驱物, 通过水热方法合成出一种新型多晶格化合物[Ni(OH)1.115(H2O)0.885]1.22(Ti1.73O4)·1.65H2O. 应用XRD, IR, TG-DTA和TEM等测试方法对该化合物进行了表征. 结果表明, 在该化合物中, TiO2层和Ni(OH)2层沿c方向交替堆积, 分别形成3个次级晶格. 其中TiO2次级晶格属于正交晶系, 其可能的空间群是Pmmm, 晶格参数a=0.3875 nm, b=0.2976 nm, c=2.288 nm和α=β=γ=90°. 另外2个Ni(OH)2次级晶格具有相同的大小和对称性, 晶格参数a=b=0.3140 nm, c=2.288 nm, α=β=90°, γ=120°. TiO2次级晶格和Ni(OH)2次级晶格在ab平面二维方向上不匹配.